Most backups involve just backing up ALL the disk storage
your site has.This is both costly and
wasteful.On the surface it may seem to
be the quick and easy way to cover everything, but in reality it creates a
monster, that more often than not, fails to provide the required protection.

First,
it is very important to understand the three very different problems backups
are used to solve.

1.System
failure: the hardware fails and you lose all the information on it, or the
database crashed and will not recover.

2.“User
error,” I deleted a file last week I really need, or plans changed and I need
to “undo” two weeks worth of work.

3.Audit
requirements: we need to produce the accounting month end supporting files for
4/1999.

Each
of these problems have very different requirements for the backups that are
needed to correct them.

1.System
failure, a full backup from the last stable point immediately before the error
is perfect.The best strategy is to
have a “ghost” copy of the base system, and one or maybe two copies frequently
overwritten with the latest set of files needed to bring the “ghost”
current.There is no value in being
able to go back farther than the last “clean” state.

2.User
errors require multiple layers of copies going back one or two business
cycles.Only the files the users save
or provide input to need to be saved.One scenario might be: one copy from last night and four weekly copies.

3.The
third type is normally the easiest, as it is dictated by the audit
requirements.There are two subtypes
here.First: backing up of a running
journal or log, this needs to be the same as the system backup above.Second: the backup of a “close” or other
accounting point, this type of backup needs to be manual and is normally part
of the “close” process.It will also
need to be kept on a schedule based on the record keeping requirements.

Determining your needs:

1.Start
with the first problem, system failure.

·Given
you have your original install disks what set of files would you need to
recover your system,

and
what is their total size?_______Mbytes (1a).

·How
much does this number grow each month? _______Mbytes
(1b).

·On
the average, how many files are created, modified, or saved each day?______

·What
is the total size of these changed files?_______Mbytes
(1c).

2.What
is the approximate cost of losing your work for?

·1
day ______

·1
week ______

·1
month ______

·The
whole system _________

3.What
is the total size of the storage you are currently using?

·Total
amount of PC disk storage. ________Mbytes.

·Total
amount of server storage used________Mbytes.

·Approximately
what percentage is duplicated?____% (3a)

IE.Identical files found on each PC (Windows, Applications, Etc).

4.For
the second and third problems, you need to look at your business cycles.

·When
do you sum up and “close”:Daily,
Monthly, Quarterly and/or Yearly.

·How
many copies of “work in progress” are required?______

·At
what interval should these copies be kept?______

5.What
backup schema is right for you.

·_____
Daily copies.

·_____
Monthly copies.

·_____
Quarterly copies.

·_____
Yearly copies.

·___________________ copies.

·_____
Total number of copies (5a).

Sizing the Server:

Now
use total space from (1a) + 12 * (1b) above ______Gbytes.

Add
to that 100 – (3a) percent of (5a) * (1b) ______Gbytes.

Total protected storage
required______Gbytes.

If
you have difficulty answering the above questions, we have consulting services
and tools that can help.